The field of inventions is window covering, and more particularly louver assemblies for covering windows and related glazing or fenestration.
Louver assemblies are intended to rotate the louvers in parallel to either admit light or block light to limit visibility from either the interior or the exterior, i.e. to provide privacy. It is desirable to block light when it would be annoying to occupants, or heat the room when not desired.
However, blind assemblies are usually manually rotated, and rely on the cognizance of the occupants to determine and act when it would be desirable to make an adjustment.
U.S. Pat. No. 4,773,733 (Murphy et al., Sep. 27, 1988) discloses a louver assembly with an automated means to rotate the louvers to exclude direct sunlight, with the louvers elements deploying a prismatic structure to reflect light back to the outside of the window by total internal reflection. Such louvers would distort the outside image, so external visibility is achieved by the spaces between the louvers. Hence, the louvers are intended to operate in the largely horizontal orientation and only rotate to catch and reflect direct sunlight back outward. In other words, with respect to sunlight, they act like metallic reflectors, but let diffuse external light (that is non-direct sunlight emanating from objects) enter the room. However, such diffuse light is broken up by the prismatic structures which distorts the external appearance to the room occupants. The louvers are adjusted from the largely horizontal orientation by a motor drive in response to the detection of the suns altitude, which is done by a photo-detector placed on a louver proximal to a louver supporting header element.
While it is desirable to reflect direct sunlight that would annoy building residents outward, it is more desirable to redirect this sunlight inward, but upward toward the ceiling in the building to minimize the need for interior lighting during the daytime.
It would be an advance to provide an improved means to adjust louvers for light re-direction, as well as better control privacy and the utilization or exclusion of the sun or other exterior lighting sources.
The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings